| 摘要 |
PROBLEM TO BE SOLVED: To analyze whether an abnormal state in an optical amplifier is due to deterioration (or damage) of a fiber or the fault of an excitation light source. SOLUTION: The optical amplifier is provided with an optical fiber to which signal light is inputted, excitation light source elements 21 introducing excitation light to the optical fiber and a light receiving element 33 detecting the intensity of signal light amplified by excitation light. When first detection intensity of signal light detected by the light receiving element 33 is smaller than setting intensity by not less than a prescribed value, the intensity of excitation light is controlled based on a comparison result of first detection intensity and second detection intensity of light signal detected by the light receiving element 33 when the intensity of excitation light is raised. COPYRIGHT: (C)2006,JPO&NCIPI |
